The McMichael U.S. Pat. No. 2,937,692 discloses a range finder operator's seat which enables the operator to raise and lower the seat to follow the eyepiece of the range finder during operation thereof. The seat adjustment and locking mechanisms there disclosed are quite complex, including numerous components and assemblies, which may present maintenance and durability problems especially in a combat environment.
The Scherer U.S. Pat. No. 2,909,212 discloses a spring loaded locking mechanism for a chair pedestal. A fingeroperated lever is provided with cam surfaces adapted to engage surfaces on a spring-biased plunger to withdraw the plunger tip from spaced sockets along the length of the pedestal for height adjustment purposes.
U.S. Pat. No. 2,935,120 issued May 3, 1960 to G. L. Naus discloses a vertically adjustable seat and backrest for a locomotive operator. A foot-operated dog mechanism cooperates with height adjusting teeth on an outer hollow seat support tube for seat adjustment purposes. The seat is rotatable relative to the backrest.
The Guyton U.S. Pat. No. 4,148,524 issued Apr. 10, 1979 describes a vertically adjustable seat also having a foot operated adjustment mechanism including a foot-rest which is pivotably lifted to engage and disengage a locking pin relative to associated locking holes or slots in an inner tubular support.
The Koutsky U.S. Pat. No. 4,186,963 issued Feb. 5, 1980 shows a vehicular seat wherein a seat carriage rolls relative to a roller housing and can be latched in adjusted position by a hand operated latch.